The present invention relates to a developer storing body, a developing device, an image forming unit and an image forming apparatus.
A general image forming apparatus such as a printer, a copier, a facsimile machine or a combined machine is configured to form a toner image by uniformly charging a surface of a photosensitive drum using a charging roller, exposing the surface of the photosensitive drum using an LED head to thereby form a latent image, and developing the latent image using a developing unit. The developing unit includes a developing roller, a toner supplying roller, a developing blade or the like. A toner as a developer is supplied to the developing roller by means of the supplying roller, and a thin toner layer is formed on the surface of the developing roller by means of the developing blade. The toner on the developing roller adheres to the surface of the photosensitive drum, and develops the latent image to form a toner image.
The toner image on the surface of the photosensitive drum is transferred to a sheet by means of a transferring roller, and then the toner image is fixed to the sheet by means of a fixing unit.
The photosensitive drum, the charging roller, the developing roller, the toner supplying roller, the developing blade and the like constitute an image forming unit. A toner cartridge is detachably attached to a main body of the image forming unit (i.e., an image forming unit main body) for supplying the toner to the image forming unit main body. The toner cartridge is replaced when the toner stored in the toner cartridge is used up.
The toner cartridge includes a toner outlet opening disposed at a bottom of a cartridge main body. Further, a shutter is rotatably provided inside the toner cartridge to open and close the toner outlet opening. The shutter has a shutter opening corresponding to the toner outlet opening. The toner outlet opening is opened when the shutter opening is aligned with the toner outlet opening, and is closed when the shutter opening is not aligned with the toner outlet opening. The shutter further includes an operating portion which is to be operated by an operator for opening and closing the toner outlet opening. When the operating portion is operated by the operator, the shutter rotates to open or close the toner outlet opening, and causes the toner cartridge and the image forming unit main body to engage each other or disengage from each other.
A replacing operation of the toner cartridge is performed as follows. First, the operator operates the operating portion of the shutter to close the toner outlet opening of the toner cartridge (attached to the image forming unit) by means of the shutter, and to release engagement between the toner cartridge and the image forming unit main body. Then, the operator detaches the toner cartridge from the image forming unit main body while holding a grip portion of the toner cartridge. Thereafter, the operator attaches a new toner cartridge to the image forming unit main body. Then, the operator operates the operating portion of the shutter to cause the new toner cartridge and the image forming unit main body to engage each other, and to open the toner outlet opening for example, Japanese Laid-Open Patent Publication No. 2000-181224).
Recently, it is demanded to further enhance operability of a replacing operation of a toner cartridge.